Dioxoles prepared by dechlorinating 4,5-dichloro-4,5-difluoro-dioxolanes have been found to form both homopolymers and copolymers (especially with tetrafluoroethylene) which have useful chemical and physical properties. These advantageous properties include chemical inertness to hydrogen fluoride, optical clarity and film-forming ability. For example, the dioxoles may be reacted with vinylidene fluoride or tetrafluoroethylene to produce plastic and/or elastomeric polymers useful in the production of corrosion-resistant seals, gaskets or linings.
The trans isomer of a 2,2-bis-substituted-4,5-dichloro-4,5-difluoro-dioxolane is considered the isomer which dechlorinates to form the corresponding dioxole (see, e.g., U.S. Pat. No. 5,177,224, in particular example 89). U.S. Pat. No. 5,177,224 disclosed use of antimony pentachloride and anhydrous hydrogen fluoride to effect the rearrangement of a cis to a trans dioxolane isomer.